Specifications

VMware, Inc. 193
Chapter 13 Troubleshooting
 Increase the amount of disk space allotted to the queues. However, if a hardware issue is the root of the
problem, correct that problem at the source.
 The size of the passive server queue can increase sharply in response to certain types of file write activity
on the active server, such as when vCenter Server Heartbeat is replicating a large number of very small
updates of a few bytes each. The volume of update traffic can be far greater than the physical size of the
files on the disk, and the passive server queue can become disproportionately large. You can see this
pattern of disk activity during the population of Full-Text Catalogs in Microsoft SQL Server. Increase the
amount of disk space available for the queues. Move the queues to their own physical disk, upgrade the
memory or the disk subsystem.
 vCenter Server Heartbeat requires a certain amount of system resource for its own basic operations and
requires some additional resources for processing replication traffic. This is in addition to the resources
used by Windows and other applications running on the server, including critical applications protected
by Heartbeat. Allocate sufficient resources for all the applications and services running on such a server
to provide maximum performance, stability, and resilience for changing client, server, and network
activity.
[L20]Out of Disk Space (VCChannelOutOfDiskSpaceException)
This message indicates that one of the servers in the pair has run out of disk space without reaching its preset
quota.
Symptom
Replication stops and the vCenter Server Heartbeat Event Log displays the error message originating from
either server in the pair.
Cause
One of the queues has exceeded the amount of physical disk space available for it without reaching its quota
limit. For example, if the maximum queue size is set to 5GB, but only 3GB of physical disk space remains, this
error message is reported if one of the queues exceeds 3GB in size.
Resolution
Free up more disk space or move the queues to a disk with sufficient free space to accommodate queue sizes
up to the limit configured for Maximum Disk Usage.
Application Slowdown
Operations performed by the application can take longer to complete, and in turn, can affect the time required
to log in to a remote client, or to open or save a file. This is true for both servers running vCenter Server
Heartbeat and for servers running any other application. vCenter Server Heartbeat can monitor system
performance counters and display warnings when predefined thresholds are exceeded, but it does not actively
manage system resources for other applications. Like any other application, it also requires a finite amount of
resources for its own operations in addition to the resources used by the operating system and the protected
application.
The machines hosting vCenter Server Heartbeat must meet recommended hardware requirements and must
be powerful enough to support the load, the protected applications, and any other critical applications
running on the same server pair.
Poor Application Performance
When applications are competing for resources, one or more applications can perform poorly.
Symptom
Neither server in the pair can accommodate the load placed upon it during normal operation.